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BT: white space works - if you're not "hung up" on speed

BT reveals the early results of its white space broadband trial in Scotland

BT's white space broadband trial is successfully delivering speeds of up to 8Mbits/sec, and could help extend coverage to outlying rural areas.

PC Pro visited Kilchattan Bay on the Scottish Isle of Bute, to see the results of a white space trial which started last April and runs until September.

While the trial is still ongoing, BT has successfully managed to provide broadband access to ten local farmers using so-called white space spectrum, the space between the frequencies used for TV.

The idea is that such radio signals can pick up where copper wires fail, extending the reach of broadband. The signal is picked up by an antenna on the customer's home - for one part of the trial, a modified TV aerial is being used - and run via a cable inside to a standard router.

"Customers don't really see a difference [at the point of use]", Brendan Dick, director of BT Scotland, said.

Hung up on speeds

Using a standard aerial, each channel can support up to 10Mbits/sec, but trials with a new piece of hardware offers up to 15Mbits/sec. The signal degrades over distance, but BT said it could offer up to 4Mbits/sec as far as 6km from the transmitter.

Everybody gets hung up about speed

The highest speed we achieved on location was 6.2Mbits/sec - and that was in sight of the mast. A point 6km from the transmitter had much slower speeds; we saw a top speed of 1.5Mbits/sec at the time, but BT claimed it has regularly achieved speeds of 3.5Mbits/sec.

The speeds are easily improved, however. Channels can be "bonded" together or one channel can be used for downloads and another for uploads. And as Chris Gibbs, BT Openreach's director of insight, innovation and futures, pointed out, speed isn't usually the problem, but contention, although that can be solved by adding extra channels.

"Everybody gets hung up about speed," Gibbs told PC Pro. "The real thing is can Robert McAlister [a local farmer taking part in the pilot] go online and sell his beasts on? Can his daughter sit there at the same time and watch BBC iPlayer? It might be you only need 8Mbits/sec shared over a few people."

Indeed, white space broadband only works for small numbers of people. BT said it was targeted at areas needing to get "tens" of people online, not hundreds or thousands. That's not as dire as it sounds, as many exchanges in Scotland support fewer than 100 lines, BT noted.

The trial is also dependent on a 100Mbit/sec microwave backhaul to the mainland, but many rural areas may need submarine lines to connect to the core network. "If you don't have that, it doesn't matter what you have in your access network," said Gibbs.

BT said the trial showed white space was technically viable, but repeatedly stressed it will eventually come down to the bottom line. "I think the work we've done so far has been really encouraging," Gibbs said. "If we can get the technology integrated correctly and we can get the commercial performance correct, then I absolutely think we will see this kind of technology rolled out."

Satellite broadband

The speeds we saw aren't superfast - or any better than what satellite broadband currently offers. Gibbs claimed there's "more capacity in two cabinets than in a satellite", but willingly admits satellite broadband will be part of the larger picture when it comes to achieving the Government's goal of 100% coverage of 2Mbits/sec connections.

Indeed, Gibbs said UK broadband coverage would emerge as a "patchwork" - using different technologies where they best fit to solve rural not-spots.

"There’s no magic technology that’s going to come in and be the answer to your dreams," Gibbs said. "A lot of people claim it, but there isn’t.”

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Comments

Its only an option to use spare bandwidth, but the range is pitiful.I've setup my own FWA cells covering ranges and speeds far in excess of 6km.The equipment is and has been readily available for years.What appears to halt commmunities solving these issues themselves is working as a team and securing a good service head link onto the fibre core or other primary link.I notice even 02 are rolling out Leased lines over Mobile.

In our village because we're served by an exchange in the next village across we get quite slow broadband speeds, normally not much better than 500kb-1mb before the 21CN upgrade, now around 1.5mb-2mb. Maybe use of this white space broadband could help many more communities like ours that are a long way from the nearest exchange?

I was just wondering, the costs of research and development of these new technologies, is it really cheaper to do R&D than to just run new cables/infructures to these rural areas?Or is there a second reason for this R&D? i.e. to be used in third world countries?

I live in a small hamlet about 7 miles from the exchange and neighbours are struggling to get 1 Mb/s.I have a line of sight 50 Mb/s 5.4 GHz radio link to the local TV mast. I only pay for 10 Mb/s but still get downloads clocked at 1 Mbyte/sec.This seems the only economic way to reach isolated houses and should be paid for by the promised government subsidy.But BT don't seem to do existing radio technology?

@Dregnet84 -- What I was told is that in some places cables don't work, mostly because of the distances. Cables might have to dodge a lake, making the line too long for good service, while this can obviously go straight over the water.

The trial is still looking at the business case, but the idea is that in the long run this will be cheaper than running cable -- BT is betting that cost saving will make up for the R&D investment.

Excellent question regarding developing countries. One of the guys working on the project out of the University of Strathclyde hopes to use a similar spectrum system to roll out broadband in Kenya - they apparently don't run TV over spectrum, so there's loads of room for internet access.

@prbistow -- The difference here is that this isn't line of sight. One transmitter can cover a wider variety of houses over different terrain. BT says it's also looking into the solution you describe for areas where it works - but as you point out, funding is usually the issue...

Here in sunny Harrogate I live 1 mile from the local BT exchange and get a scorching 1.5mb on a good day with the wind behind it. I long for speeds up to 2mb. perhaps I could persuade BT to put in white space to cover the town so we could have improved speed.